Methods for diagnosing pulmonary hypertension

ABSTRACT

Hypoxia induced mitogenic factor (HIMF) is a member of the “found in inflammatory zone” (FIZZ)/resistin family of proteins and has potent mitogenic, angiogenic, and vasoconstrictive effects in the lung vasculature. The receptor/binding partners for this family of proteins have been largely unknown. We identified Bruton&#39;s tyrosine kinase (BTK) as a functional HIMF binding partner through GST-HIMF pull-downs and mass spectrometry. Using primary cultured HIMF-stimulated murine bone marrow cells, we demonstrated that BTK was recruited to the leading edge of the cells. We also demonstrated that BTK and the closely related tyrosine kinase Fyn, colocalized at the growth cone process in these cells. HIMF stimulation induced BTK autophosphorylation, which peaked at 2.5 minutes. A transwell migration assay showed that treatment with recombinant murine HIMF induced migration of primary cultured bone marrow cells, which was completely blocked by the BTK inhibitor, LFM-A13. In vivo studies, using the rat hindlimb ischemia model, revealed that HIMF can stimulate angiogenesis in the hypoxic tissue probably through inducing the migration of endothelial progenitor cells (EPCs) to areas of active angiogenesis. Our results indicate that HIMF may acts as a chemotactic molecule in stimulating the migration of leukocytes/EPCs from bone marrow to targeted tissues through activation of the BTK pathway.

This invention was made using funds from the United States Government.Under the terms of grant no. R01 HL39706 from the National Institutes ofHealth, the U.S. Government retains certain rights in the invention.

TECHNICAL FIELD OF THE INVENTION

This invention is related to the area of pulmonary, cardiac, andinflammation disorders. In particular, it relates to methods fortreatment of these disorders and screening for therapeutic agents totreat these disorders.

BACKGROUND OF THE INVENTION

Hypoxia-induced mitogenic factor (HIMF), also called “found ininflammatory zone 1” (FIZZ1) or resistin like molecule alpha (RELMα) orresistin, is induced in the lungs of experimental models ofhypoxia-induced pulmonary hypertension (1, 2). We have shown that HIMFis expressed in the remodeling of hyperplastic vascular smooth muscle invivo and can stimulate pulmonary microvascular mitogenesis in vitro.Also, we have demonstrated that HIMF possesses angiogenic andvasoconstrictive properties. In addition, HIMF increases pulmonaryartery pressure and pulmonary vascular resistance more potently thanendothelin, angiotensin or serotonin (1). Not only was HIMF expressionincreased in the lung vasculature, it was markedly up-regulated inhypertrophic, hyperplastic bronchial epithelium during allergicpulmonary inflammation in mouse models of acute pulmonary inflammation(3). A recent report has also demonstrated HIMF to be expressed in thelymph nodes (4), with the highest expression in B cells and macrophages.

The FIZZ/resistin gene family has been implicated in a variety of humandiseases, but their binding partners/receptors until now had not beenidentified. Resistin which is one of two human analogs of HIMF, hasrecently been implicated in human vascular disease related to diabetesand to obesity (5). Resistin is greatly up-regulated in obesity andafter insulin treatment, thus providing a potential molecular linkbetween obesity and diabetes. It may function as a regulator of glucosehomeostasis and an antagonist to insulin action (6). XCP1/FIZZ2 wasfound to be a chemotactic factor to myeloid cells fromC/EBP-epsilon-null mice and is able to interact directly withalpha-defensin (7). There are three members of the FIZZ/resistin familythat are encoded by two different genes in human, and five members ofthe FIZZ/resistin family that are derived from four genes in mouse.Receptors have not yet been identified for any of these physiologicallyand pathologically important rodent or human isoforms, leaving ourfunctional understanding of this family of proteins incomplete.

Increasing evidence indicates that bone marrow-derived endothelialprogenitor cells (EPCs) or circulating hematopoietic stem cells play animportant role in postnatal neovascularization of adult ischemic tissuesand injured tissues(8-11). Endogenous stimuli like tissue ischemia andexogenous cytokine therapy mobilize EPCs, and thereby contribute to theneovascularization of ischemic and injured tissues (12). A number ofchemokines have been reported to act as chemotactic and angiostaticmolecules in inducing endothelial cell migration and regulatingangiogenesis (13,14). In inflammatory diseases, angiogenesis andinflammatory disorders are two inter-related processes regulated bychemokines. XCP1, another member of FIZZ/resistin family sharing 70%identity in amino acid sequence with HIMF, has been reported to be asecreted protein that is chemotactic to myeloid cells, and may also havea role in cell migration, activation, and chemotaxis (7). Although EPCsare rare in the circulation, they can be mobilized into circulation frombone marrow by vascular trauma or systemic administration of cytokines(12, 13, 15, 16). Multipotent adult progenitor cells (MAPC) derived frompostnatal human bone marrow were demonstrated to be progenitors forangioblasts and to undergo a differentiation process from CD34(−),VE-cadherin(−) cells to CD34(+), VE-cadherin(+) cells after culture inthe presence of VEGF. These cells subsequently differentiate intomorphologically and functionally mature endothelial cells thatcontribute to neoangiogenesis in vivo during tumor angiogenesis andwound healing (15,17).

The role of HIMF in hypoxic tissue and how HIMF exerts its angiogenicand vasoconstrictive properties remain unclear. The current work definesa targeted molecular binding partner of HIMF and investigates whetherHIMF functions as a chemotactic molecule for recruiting bone-marrowderived cells to hypoxic or ischemic tissue like its homolog XCP1. Todetermine HIMF's major binding partner(s) we used GST-pull-down and massspectrometry techniques. We isolated a HIMF-binding molecule, BTK, amolecule known to be crucial in regulation of B-cell maturation andinvolved in cell migration. BTK stimulates B cell differentiation inbone marrow, and mutations in BTK are responsible for X-linkedagammaglobulinemia (XLA) in humans and X-linked immunodeficiency (xid)in mice (18, 19). Since HIMF expression is induced in hypoxic tissue,and bone marrow derived EPCs are preferentially recruited to the site ofischemic tissue, we investigated whether HIMF is a chemotactic moleculefor bone marrow cells.

There is a continuing need in the art to identify important targets fortreating pulmonary, cardiac, and inflammatory diseases.

SUMMARY OF THE INVENTION

According to one embodiment of the invention a method of treating apatient with inflammatory lung disease is provided. An agent isadministered to the patient. The agent is selected from the groupconsisting of an antibody which specifically binds to HIMF(SEQ ID NO: 1or 2); an antibody which specifically binds to BTK(SEQ ID NO: 3); anRNAi which is complementary to an mRNA of HIMF (SEQ ID NO: 4 or 5); andan RNAi which is complementary to an mRNA of BTK(SEQ ID NO: 6).Expression of HIMF or BTK is thereby suppressed or binding of HIMF toBTK is inhibited.

Another aspect of the invention is a method of screening for a candidatedrug for treating inflammation. Binding of HIMF (SEQ ID NO: 1 or 2) withBTK (SEQ ID NO: 3) is determined in the presence and absence of a testsubstance. A test substance that reduces binding of HIMF to BTK isidentified as a candidate drug for treating inflammation.

According to another embodiment of the invention a method of treating apatient with cholesterol levels which are higher than a recommendednormal range is provided. An agent is administered to the patient. Theagent is selected from the group consisting of: an antibody whichspecifically binds to HIMF(SEQ ID NO: 1 or 2); an antibody whichspecifically binds to BTK(SEQ ID NO: 3); an RNAi which is complementaryto an mRNA of HIMF (SEQ ID NO: 4 or 5); and an RNAi which iscomplementary to an mRNA of BTK(SEQ ID NO: 6). Expression of HIMF or BTKis thereby suppressed or binding of HIMF to BTK is inhibited.

According to one embodiment of the invention a method of treating personwith inflammation, dementia, cancer, nuclear cataract, atherosclerosis,sarcoidosis, or pulmonary hypertension is provided. An agent isadministered to the person. The agent is selected from the groupconsisting of: an antibody which specifically binds to HIMF(SEQ ID NO: 1or 2); an antibody which specifically binds to BTK(SEQ ID NO: 3); anRNAi which is complementary to an mRNA of HIMF (SEQ ID NO: 4 or 5); andan RNAi which is complementary to an mRNA of BTK(SEQ ID NO: 6).Expression of HIMF or BTK is thereby suppressed or binding of HIMF toBTK is thereby inhibited. Similarly, a statin drug can be used to treatthese conditions.

A further aspect of the invention provides a method to diagnose severityof asthma. The amount of HIMF (SEQ ID NO: 1 or 2) in a nasal swab orlung washing of a subject is determined. The amount of HIMF correlateswith severity of asthma.

According to still another embodiment of the invention a method isprovided for treating a patient with cardiac hypertrophy, ischemia, orheart failure. An agent is administered to the patient. The agent isselected from the group consisting of: an antibody which specificallybinds to BTK(SEQ ID NO: 3); and an RNAi which is complementary to anmRNA of BTK(SEQ ID NO: 6). Expression of BTK is thereby suppressed orbinding of HIMF to BTK is thereby inhibited.

Yet another embodiment of the invention is a method of screening for acandidate drug for treating inflammation. Bone marrow cells arestimulated with HIMF (SEQ ID NO: 1 or 2) in the presence and absence ofa test substance. Phosphorylation of BTK (SEQ ID NO: 6) in the bonemarrow cells is determined. A test substance that reducesphosphorylation of BTK in response to HIMF stimulation is identified asa candidate drug for treating inflammation.

Still another aspect of the invention is a method to diagnose pulmonaryhypertension. The amount of HIMF (SEQ ID NO: 1 or 2) in a serum sampleof a subject is determined. A serum sample that has an amount of HIMFgreater than an amount of HIMF in normal, non-pulmonary hypertensivecontrols is identified as belonging to a subject with pulmonaryhypertension.

These and other embodiments which will be apparent to those of skill inthe art upon reading the specification provide the art with

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B. BTK is a HIMF-binding molecule. GST-HIMF fusion protein andGST were incubated with glutathione-sepharose beads and then incubatedwith bone marrow cell lysate respectively in TBST buffer at 4° C. forthree hours. The beads were washed five times by TBST and loading bufferwas added to the samples. After electrophoresis, the gel was stained byCoomassie Blue. The arrow shows a HIMF-binding candidate protein (FIG.1A). GST-HIMF and GST were first bonded to glutathione sepharose andthen incubated with the lysate of bone marrow cells (left) or homogenateof ischemic tissue (right) at 4° C. for three hours and then washed byTBST solution three times. After SDS-PAGE and transfer to membrane, thesamples were detected by anti-BTK and anti-GST antibodies (FIG. 1B).

FIG. 2. Co-localization between BTK and HIMF. EGFP-BTK and His-HIMFplasmids were co-transfected into bone marrow cells. The cells werefixed by pre-cooled methanol and stained by anti-his monoclonal antibodyand rhodamine-labeled donkey anti-mouse IgG second antibody. EGFP-BTKand his-HIMF co-localized very well in transfected cells.

FIGS. 3A-3B. BTK redistribution in response to the stimulation of HIMF.Primary cultured bone marrow. Bone marrow cells were cultured on coverglass and then treated with 50 nM BSA (FIG. 3A) or HIMF (FIG. 3B) forfive minutes. Cells were fixed by pre-cooled methanol before indirectimmunofluorescence. BTK or FYN, a binding partner for BTK, wasredistributed in bone marrow cells after the treatment of HIMF.

FIGS. 4A-4C. BTK self-phosphorylation in response to the treatment ofHIMF. Three plates of primary cultured bone marrow cells that werepassed from the same plate of cells were cultured to confluence and thentreated with HIMF (5 minutes and 30 minutes), or without HIMF. The celllysates were used for the Western blot. The membrane was first probed byanti-BTK phosphorylation (Y223) antibody and then was probed by anti-BTKantibody after stripping (FIG. 4A). Five plates of primary cultured bonemarrow cells that were passed from same plates of cells were cultured toconfluence and then treated with HIMF (2.5, 5, 10 and 20 minutesrespectively) or without HIMF. The cell lysates were used for theWestern blot. The membrane was first detected by anti-BTKphosphorylation (Y223) antibody and then by anti-tubulin antibody (FIG.4B). The same samples were used for the detection of fyn phosphorylation(FIG. 4C). Phosphorylation of Y416 upregulates enzyme activity.Phosphorylation of Y528 negatively regulates enzyme activity.

FIGS. 5A-5B. HIMF stimulated bone marrow cell migration. Bone marrowcells were partially digested by trypsin-EDTA solution, washed by PBSand then sucked up and transferred to twelve well plates using a 1000 μltip. The cells were cultured in 2% fetal bovine serum DMEM with 50 nMBSA or HIMF for four days. More cells migrated out of the original cellcolony in the presence of HIMF than those in BSA (FIG. 5A). 5×10⁵ bonemarrow cells were cultured in transwell plates in the presence of 50 nMBSA or HIMF. The cells were cultured overnight, fixed in pre-cooledmethanol and stained by Coomassie Blue solution. The cells growing onthe surface of the membrane were removed after staining (FIG. 5B). ANikon Eclipse microscope was used for the imaging.

FIGS. 6A-6D. CD45 positive cell migration was stimulated by HIMF andinhibited by BTK inhibitor. Bone marrow cells were cultured on coverglass in 12 well plates as described in FIG. 5A-5B. The cells were thentreated with BSA (FIG. 6A) or HIMF (FIG. 6B and FIG. 6C) for 4 days andfixed with pre-cooled methanol before immunocytochemistry with theindicated first antibodies. DAPI staining was used to show the nuclei.The cells migrated out of the original cell colony were shown to be CD45positive (FIG. 6A, FIG. 6B and FIG. 6C). 5×10⁵ bone marrow cells in 2%fetal bovine serum DMEM culture medium were transferred to eachtranswell in the presence of 50 nM BSA, HIMF, or HIMF plus 25 μMLFM-A13, respectively. The cells were cultured for 6 hours, fixed inpre-cooled methanol and stained by Coomassie Blue solution. The cellsgrowing on the surface of the membrane were removed after staining. Bonemarrow cell migration was induced by HIMF and this induction wasinhibited by BTK inhibitor LFM-A13 (FIG. 6D).

FIGS. 7A-7B. HIMF stimulated angiogenesis in hypoxic tissues. Mouse hindlimb ischemia model was established and agarose gel containing 100 nMBSA or 100 nM HIMF (gels were cut into 2×5×8 mm pieces) were buriedsubcutaneously at the sites of ischemia. Two weeks later, the ischemictissues were collected for immunocytochemistry. The tissue treated byHIMF (FIG. 7B) was shown increasing in CD34 positive cells comparing tothat of BSA treated tissue (FIG. 7A).

FIG. 8. Human HIMF up-regulated in scleroderma patient lungs relative tocontol lungs. The HIMF proteins were measured immunohistochemically andquantitated.

FIG. 9. Expression of HIMF and beta-tubulin under hupoxic conditionsand/or with statin treatment. Immunoblots of HIMF (top) and beta-tubulin(bottom) with conditions as indicated.

DETAILED DESCRIPTION OF THE INVENTION

The inventors have discovered a functional binding partner of HIMF whichis BTK. Inhibition of binding of either partner to the other preventsthe functional and often pathological consequences of binding.Antibodies specifically binding to either HIMF or BTK can be used.Antibodies which prevent the binding of the antigen to its partner canbe used to provide a therapeutic effect. Similarly, interfering RNA(RNAi) which suppresses expression of the HIMF or BTK product can beused.

HIMF is used to collectively denote either of the two human proteinforms known as resistin and relm-beta. These are encoded by genesdenoted as RETN and RETNLB. Exemplary human sequences from the publicdatabases are represented as SEQ ID NO: 1 (resistin), SEQ ID NO: 2(relm-beta), SEQ ID NO: 3 (Bruton agammaglobulinemia tyrosine kinase),SEQ ID NO: 4 (RETN), SEQ ID NO: 5 (RETNLB), and SEQ ID NO: 6 (BTK) inthe sequence listing. Minor variations occur in any human population ofproteins and genes which do not change function or the vast majority ofthe structure. Such minor variations, known as polymorphisms, areencompassed. Typically these are single nucleotide changes and/or singleamino acid changes.

Diseases which can be treated using the HIMF/BTK antibodies, bindinginhibitors, and interfering RNAs include any inflammatory lung disease,including but not limited to Scleroderma, idiopathic pulmonary fibrosis,sarcoidosis, asthma, emphysema, adult respiratory distress syndrome,radiation-induced pulmonary inflammation or fibrosis,chemotherapy-induced pulmonary inflammation or fibrosis, and chronicobstructive pulmonary disease. Other types of inflammation includingdementia, cancer, nuclear cataracts, and pulmonary hypertension can alsobe treated. In addition, heart conditions including but not limited tocardiac hypertrophy, ischemia, atherosclerosis, and heart failure arealso amenable to such treatments. In addition, since statin drugs havebeen found to decrease amount of HIMF in lungs, statin drugs can be usedto treat any of these conditions and diseases as well, particularly thelung diseases.

Statin drugs are inhibitors of HMG-CoA, i.e., hydroxy-3-methylglutarylcoenzyme A. reductase. These include, but are not limited toatorvastatin, cerivastatin, fluvastatin, lovastatin, mevastatin,pitavastatin, pravastatin, rosuvastatin, simvastatin. These can also beused in combinations with, for example, ezetimibe, niacin, and/oramlodipine besylate.

One of ordinary skill in the art can readily generate antibodies whichspecifically bind to the HIMF or BTK proteins. Such antibodies can bemonoclonal or polyclonal. They can be chimeric, humanized, or totallyhuman. Any functional fragment or derivative of an antibody can be usedincluding Fab, Fab′, Fab2, Fab′2, and single chain variable regions. Solong as the fragment or derivative retains specificity of binding forthe protein it can be used. Antibodies can be tested for specificity ofbinding by (a) comparing binding to appropriate antigen, to (b) bindingto irrelevant antigen or antigen mixture, under a given set ofconditions. If the antibody binds to the appropriate antigen at least 2,5, 7, and preferably 10 times more than to irrelevant antigen or antigenmixture then it is considered to be specific. Moreover, the ability ofsuch antibodies or antibody fragments to inhibit the binding of HIMF toBTK can be readily and routinely tested.

Techniques for making such partially to fully human antibodies are knownin the art and any such techniques can be used. According to oneparticularly preferred embodiment, fully human antibody sequences aremade in a transgenic mouse which has been engineered to express humanheavy and light chain antibody genes. Multiple strains of suchtransgenic mice have been made which can produce different classes ofantibodies. B cells from transgenic mice which are producing a desirableantibody can be fused to make hybridoma cell lines for continuousproduction of the desired antibody. See for example, Nina D. Russel,Jose R. F. Corvalan, Michael L. Gallo, C. Geoffrey Davis, Liise-AnnePirofski. Production of Protective Human Antipneumococcal Antibodies byTransgenic Mice with Human Immunoglobulin Loci Infection and ImmunityApril 2000, p. 1820-1826.

Antibodies can also be made using phage display techniques. Suchtechniques can be used to isolate an initial antibody or to generatevariants with altered specificity or avidity characteristics. Singlechain Fv can also be used as is convenient. They can be made fromvaccinated transgenic mice, if desired. Antibodies can be produced incell culture, in phage, or in various animals, including but not limitedto cows, rabbits, goats, mice, rats, hamsters, guinea pigs, sheep, dogs,cats, monkeys, chimpanzees, apes.

Antibodies can be labeled with a detectable moiety such as a radioactiveatom, a chromophore, a fluorophore, or the like. Such labeled antibodiescan be used for diagnostic techniques, either in vivo, or in an isolatedtest sample. Antibodies can also be conjugated, for example, to apharmaceutical agent, such as chemotherapeutic drug or a toxin. They canbe linked to a cytokine, to a ligand, to another antibody. Those ofskill in the art will readily understand and be able to make suchantibody derivatives, as they are well known in the art. The antibodiesmay be therapeutic on their own, or they may be used to delivertherapeutic agents to particular locations in the body. The antibodiescan be administered to individuals in need thereof as a form of passiveimmunization.

RNA interference constructs or siRNA duplex RNA molecules can be used tointerfere with expression of HIMF or BTK. Typically at least 15, 17, 19,or 21 nucleotides of the complement of HIMF or BTK mRNA sequence aresufficient for an antisense molecule. Typically at least 19, 21, 22, or23 nucleotides of HIMF or BTK are sufficient for an RNA interferencemolecule. Preferably an RNA interference molecule will have a 2nucleotide 3′ overhang. If the RNA interference molecule is expressed ina cell from a construct, for example from a hairpin molecule or from aninverted repeat of the desired HIMF or BTK sequence, then the endogenouscellular machinery will create the overhangs. siRNA molecules can beprepared by chemical synthesis, in vitro transcription, or digestion oflong dsRNA by Rnase III or Dicer. These can be introduced into cells bytransfection, electroporation, or other methods known in the art. SeeHannon, G J, 2002, RNA Interference, Nature 418: 244-251; Bernstein E etal., 2002, The rest is silence. RNA 7: 1509-1521; Hutvagner G et al.,RNAi: Nature abhors a double-strand. Curr. Opin. Genetics & Development12: 225-232; Brummelkamp, 2002, A system for stable expression of shortinterfering RNAs in mammalian cells. Science 296: 550-553; Lee N S,Dohjima T, Bauer G, Li H, Li M-J, Ehsani A, Salvaterra P, and Rossi J.(2002). Expression of small interfering RNAs targeted against HIV-1 revtranscripts in human cells. Nature Biotechnol. 20:500-505; Miyagishi M,and Taira K. (2002). U6-promoter-driven siRNAs with four uridine 3′overhangs efficiently suppress targeted gene expression in mammaliancells. Nature Biotechnol. 20:497-500; Paddison P J, Caudy A A, BernsteinE, Hannon G J, and Conklin DS. (2002). Short hairpin RNAs (shRNAs)induce sequence-specific silencing in mammalian cells. Genes & Dev.16:948-958; Paul C P, Good P D, Winer I, and Engelke D R. (2002).Effective expression of small interfering RNA in human cells. NatureBiotechnol. 20:505-508; Sui G, Soohoo C, Affar E-B, Gay F, Shi Y,Forrester W C, and Shi Y. (2002). A DNA vector-based RNAi technology tosuppress gene expression in mammalian cells. Proc. Natl. Acad. Sci. USA99(6):5515-5520; Yu J-Y, DeRuiter S L, and Turner D L. (2002). RNAinterference by expression of short-interfering RNAs and hairpin RNAs inmammalian cells. Proc. Natl. Acad. Sci. USA 99(9):6047-6052.

RNA interference molecules can be delivered in vitro to cells or invivo, e.g., to tumors, eyes, lungs, bronchia, heart, or retina of amammal. Typical delivery means known in the art can be used. Forexample, delivery to a tumor can be accomplished by intratumoralinjections. Delivery to lung can be accomplished by instillation. Othermodes of delivery can be used without limitation, including:intravenous, intramuscular, intraperitoneal, intraarterial, localdelivery during surgery, endoscopic, subcutaneous, and per os. In amouse model, the antisense or RNA interference can be adminstered to atumor cell in vitro, and the tumor cell can be subsequently administeredto a mouse. Vectors can be selected for desirable properties for anyparticular application. Vectors can be viral or plasmid. Adenoviralvectors are useful in this regard. Tissue-specific, cell-type specific,or otherwise regulatable promoters can be used to control thetranscription of the inhibitory polynucleotide molecules. Non-viralcarriers such as liposomes or nanospheres can also be used.

Binding assays according to the invention may be any known in the art.These include in vitro binding of purified proteins, pull-down assays,co-immunoprecipitation assays, in vivo fusion protein assays. Any suchassay in which the HIMF and the BTK detectably bind can be used as anassay for screening for candidate drugs and their effect on binding.Candidate drugs can be subsequently tested in animal models and inclinical trials to confirm efficacy and determine safety.

Test substances for drug screening can be any natural or syntheticproduct, whether a single molecular entity or a mixture of molecularentities. Libraries of compounds can be screened. Natural productextracts can be screened. Products with known or unknown biologicalfunctions or drug activity can be screened. Test substances can be smallchemical entities, or biological macromolecules, such as proteins,peptides, nucleic acids, carbohydrates, lectins, etc.

Cholesterol lowering effects of inhibition of the HIMF/BTK binding andor expression can be used to treat patients in need thereof. These canbe used as substitutes or adjuncts to statin therapy. The normal rangeof cholesterol is defined in particular populations and may change overtime. Persons outside of the determined normal range, adjudged to be inneed of cholesterol-lowering therapy, may be treated.

The level of HIMF has been found to correlate with the severity ofasthma symptoms. Thus assaying for HIMF and determining the amount ofHIMF can be used as a way to characterize, stratify, and plan treatmentfor asthma patients. Nasal swabs and lung washings are suitable tocomprise samples for such assays. Amount of HIMF in such samples can beassayed in the same patient over time to see progression or remission ofdisease. Alternatively, data from populations of asthma patientsstratified on the basis of other symptoms can be used to provide astandard curve for amounts of HIMF in the nasal swabs or lung washings.Similarly the levels of HIMF in serum can be used as a biomarker ofpulmonary hypertension, whether idiopathic or related to Scleroderma.Elevated levels compared to control subjects or populations of normalcontrols subjects who do not have pulmonary hypertension or sclerodermacan be used as a reference. Elevated levels are any which arestatistically above normal controls; this may be at least 50% greater,at least 75% greater, at least 100% greater, at least 150% greater, atleast 200% greater, at least 250% greater, or more. Assays for HIMF canbe, for example, immunological, such as by ELISA or western blot. Othermeans for readily identifying and quantifying HIMF can be used, as areconvenient. These include binding assays to BTK.

BTK autophosphorylates in response to HIMF stimulation, at least in bonemarrow cells. This biological response can be used as an assay to screenfor test substances which reduce, inhibit, or prevent suchHIMF-stimulated autophosphorylation. Candidate drugs can be subsequentlytested in animal models and in clinical trials to confirm efficacy anddetermine safety.

The HIMF/FIZZ/resistin family of proteins have been implicated inpulmonary vascular remodeling in rodents and in human vascular diseaseassociated with obesity, diabetes and atherogenesis (1,25,26). Little isknown of the mechanisms of action of this family of proteins in vasculardisease, and in particular, no receptor or functional binding partnerhad been identified. Using HIMF in pull-down assays with proteinisolated from mouse bone marrow followed by mass spectrometry, we haveidentified Bruton's Tyrosine Kinase (BTK) as an important functionalbinding partner of HIMF. Using in vitro (cell migraton assay) and invivo (hindlimb ischemia model), we have demonstrated HIMF leads toinflammatory and EPC chemotaxis, which is mediated through activation ofBTK

Mice deficient in the Src family kinases are unable to develop anangiogenic response to chemokines because their neutrophils are unableto release VEGF-A, indicating that soluble tyrosine kinases areimportant factors in angiogenesis (13). As a member of the Src family ofkinases, BTK has been known to be crucial in the regulation of B-cellmaturation, and defects in BTK lead to X-linked agammaglobulinemia inhumans and X-linked immunodeficiency defect in mice. VEGF receptor 2(VEGFR-2/Flk1) is the key mediator of VEGF action in endothelial cells.Transcriptional regulation of the VEGFR-2 can be mediated bytranscription factors TFII-I/BAP-135 and NF-κB (27). Interestingly NF-κBis an important down-stream mediator for the BTK signaling pathway (28).TFII-I/BAP-135 is also a BTK-associated protein and a substrate of BTK(27, 29). XID mice show increased severity of inflammatory diseases. Thebone marrow of XID mice shows a reduction in the numbers of bothmonocytic and granulocytic lineages, extending to the earliestprogenitor populations (19). As a result, the activation of BTK uponstimulation of HIMF may play a significant role in the recruitment ofinflammatory cells, mediating the VEGF and chemokine release andregulation of the development of the myeloid lineages (19, 30), andVEGFR-2 expression in endothelial cells.

The BTK family of kinases plays diverse roles in various cellularprocesses including stimulation of cell growth, differentiation,apoptosis, cytoskeletal reorganization, and cell motility. The mutationof BTK resulting in immunodeficiency diseases further demonstrates thephysiological importance of this kinase. In the regulation ofdifferentiation of bone marrow hematopoietic cells into B cells, the BTKpathway is essential. Other members of the BTK family of kinases havebeen shown to be involved in the signaling pathway of integrins that arekey molecules regulating the actin cytoskeleton and cell mobility (31).

Recent advances in the study of bone marrow-derived endothelialprogenitor cells have shown that these cells are involved inneovascularization during ischemic conditions (32). Growth factors andchemotactic molecules released from hypoxic tissues mobilize EPCs fromthe bone marrow to the hypoxic tissues, which are then thought to formfunctional vessels with blood flow (33). We have shown that HIMF is oneof these molecules that is released from hypoxic tissues and mayfunction as a chemotactic molecule recruiting leukocytes/EPCs to theischemic area (FIG. 7A-7B).

Using bone marrow cells as the source for seeking binding partners inour study, we demonstrated that BTK is a HIMF binding molecule by massspectroscopy. As an inflammatory marker (6), HIMF may likely be involvedin the regulation of the immune system in response to inflammatorystimulation. A large number of studies have shown that leukocytes act topromote angiogenesis in inflammatory tissues by delivering VEGF to thetarget sites, where vascular remodeling is important for tissueregeneration. The activation of BTK will induce the differentiation andmigration of bone marrow-derived leukocytes or EPCs that may be involvedin the inflammatory reaction and neovascularization in hypoxic tissues.Our finding of BTK as a HIMF binding molecule suggests that HIMF-BTKinteraction may mediate tissue recovery processes through stimulatingthe differentiation of EPCs that are involved in angiogenesis andrecruiting leukocyte/EPCs to the targeted site. HIMF acting as achemotactic molecule, like its homolog mXCP1, stimulated migration ofbone marrow derived cells to targeted tissue in response to tissueinflammation or hypoxia.

HIMF was up-regulated in both inflammatory and hypoxic tissues andstimulated the phosphorylation of AKT, a kinase with a plextrin homology(PH) domain, in cultured cells (3). Interestingly, BTK is also a PHdomain containing molecule. HIMF can also stimulate theself-phosphorylation of BTK in bone marrow cells (FIG. 4A-4C),indicating that BTK is a HIMF-targeted molecule that is activated inresponse to the stimulation of hypoxia or inflammatory reactions. Fyn,another soluble tyrosine kinase of Src family members, was not changedin activity by the stimulation of HIMF, although Fyn was reported as aBTK-binding protein and shared common distribution with BTK in cells(FIG. 3A-3B). Consequently BTK is a specifically targeted molecule forHIMF. Cells co-transfected with GFP-BTK and His-HIMF plasmids alsoshowed a clear co-localization of BTK and HIMF (FIG. 2).

When bone marrow cells were treated with HIMF, BTK was recruited to theleading edge of the cells (FIG. 3A-3B). This result further indicatedthat HIMF may stimulate the migration of bone marrow cells. By using atranswell migration assay, we found that HIMF markedly promoted bonemarrow cell migration. These migrating bone marrow cells weredemonstrated as leukocytes by immunocytochemistry using CD45 antibody(FIG. 6A-6D). The chemotactic characteristic of HIMF was shown to bedependent on the activation of BTK because the BTK inhibitor can totallyinhibit the chemokine-like function of HIMF in bone marrow cellmigration assay. Hence, HIMF stimulates the migration of bone marrowcells through the activation of BTK and is a chemotactic factor for bonemarrow derived leukocytes/EPCs. The recruitment of these cells maycontribute to the neovascularization in hypoxic tissues.

The above disclosure generally describes the present invention. Allreferences disclosed herein are expressly incorporated by reference. Amore complete understanding can be obtained by reference to thefollowing specific examples which are provided herein for purposes ofillustration only, and are not intended to limit the scope of theinvention.

EXAMPLE 1 Methods and Materials

Constructs and reagents. Flag-tagged HIMF was prepared as describedpreviously (3). GST-HIMF vector was constructed by inserting the codingsequence of mouse HIMF (digested from TA vector with EcoRI and XhoI)into pGEX-5X-1 with the sites of EcoRI and XhoI.

Antibodies and inhibitor. Anti-β tubulin and actin monoclonalantibodies, anti-CD45 rat polyclonal antibody, and anti-Fyn rabbitpolyclonal antibody were purchased from Sigma. Anti-BTK monoclonalantibody, anti-BTK phosphorylation (Tyr223), and phospho-Src family(Tyr416) polyclonal antibodies were purchased from Cell SignalingTechnology, Inc. Anti-Fyn (pY528) phospho-specific antibody waspurchased from BD Transduction Laboratories. Anti-his monoclonalantibody and anti-GST monoclonal antibody were purchased from Novagen.FITC and rhodamine-labeled secondary antibodies were purchased fromJackson ImmunoResearch. BTK inhibitor LFM-A13 was purchased fromCalbiochem.

Cell culture and transfections. COS-7 cells or mouse bone marrow cellswere maintained in Dulbecco's modified Eagle's high glucose medium(GIBCO) containing 10% fetal bovine serum at 37° C. and 5% CO₂. Cellswere transfected with plasmids, as mentioned, using LipofectAMINE 2000reagent (Invitrogen) according to the manufacturer's protocols. Thetransfected cells were then fixed in pre-cooled methanol forimmunocytochemistry after 24 hours.

GST and GST-HIMF fusion protein expression. BL21 cells harboring GST orGST-HIMF constructs were grown overnight in a 50 ml tube with LB mediumcontaining 50 μg/ml ampicillin and then transferred to a 500 ml flaskgrowing until the OD was 0.6 at 600 nm. The cultures were then inducedwith isopropyl-β-D-thiogalactopyranoside (IPTG) for an additional 4hours. Cell lysates were prepared in TBST buffer (50 mM Tris, pH 7.5,150 mM NaCl, 5 mM EDTA, 1% Triton X-100, 10 μg/ml leupeptin, 10 μg/mlaprotinin, and 1 mM phenylmethylsulfonyl fluoride).

GST pull-down assay. Bone marrow cells were cultured in ten 150×25 mmplates until confluence and collected for lysate using TBST buffer.Lysate from ten plates of bone marrow cells was used for HIMF-bindingpartner screening assay. Hypoxia tissue homogenate was prepared asdescribed above. BL21 bacterial lysates for GST and GST-HIMF were firstincubated with glutathione agarose in 0.1% TBST buffer for three hoursand then washed three times by 0.1% TBST buffer. The GST and GST-HIMFbinding glutathione agaroses were incubated with bone marrow cell lysateor hypoxia tissue homogenate for three hours and then washed 3-5 timesbefore SDS-PAGE.

Protein phosphorylation assays. Bone marrow cells were cultured in100×20 mm culture plates and treated with 50 nm BSA or HIMF fordifferent time serials and washed quickly by PBS and lysed in TBSTbuffer containing 1 mM sodium vanadate. The samples were incubated onice for 20 min, mixed several times during the incubation, and thencentrifuged. The supernatants of the samples were quantified for proteinconcentration and subjected to electrophoresis on a 4-15%SDS—polyacrylamide gel (Bio-Rad). Anti-BTK phosphorylation (Y-223)polyclonal antibody, anti-BTK, and anti-tubulin monoclonal antibody wereused for immunoblotting.

Mouse bone marrow-derived mesenchymal stem cell (MSC) preparation andculture. Six C57BL/6 mice (7 weeks old) were anesthetized withintramuscular injection of 1 mg ketamine plus 0.5 mg xylazine/peranimal. Tibiae and femurs were isolated using sterile techniques. Themouse bone marrow cells were prepared by flushing the tibiae and femurswith serum-free DMEM (low glucose, supplemented with 1×Penicillin-Streptomycin and 1 mM EDTA) using 25G needles. Pooled marrowfrom three animals was first dispersed by gentle pipeting, and thenseparated by gradient centrifugation with lymphocyte separation liquid(Sigma, density: 1.083 g/ml) as follows: 6 ml of the medium containingthe marrow cells was layered on top of 3 ml of separation liquid andcentrifuged at room temperature at 2800 rpm for 20 min. The mononuclearcells in the middle layer were collected and then washed with serum-freeDMEM three times by centrifugation, first at 2000 rpm for 15 mM, thentwo times at 700 rpm for 10 min. The cells collected after the last wash(2-3×10⁸) were resuspended in 10 ml DMEM supplemented with 10% FBS and1× penicillin/streptomycin, and then cultured at 37° C. with 5% CO₂ inone 10-cm culture dish (uncoated plastic). Three days later,non-adherent cells were removed by changing medium and the adherentcells were grown for about 2 weeks.

Mouse hindlimb ischemic model. Animals were subjected to left femoralartery ligation and excision to create unilateral hind limb ischemia.For each animal, 25 mg/kg ketamine plus 10 mg/kg xylazine was injectedsubcutaneously. Skin incisions were performed at the middle portion ofthe left hind limb overlying the femoral artery. The femoral artery wasgently isolated. First the proximal portion and then the distal portionof the femoral artery were ligated, and then other arterial branches aswell as veins were dissected free and excised. The overlying skin wasclosed using two surgical staples. Tissue in the hypoxia area wasremoved and homogenized in TBST buffer two weeks after the operation.

Cell migration assay. Bone marrow cells were detached with trypsin-EDTA,washed in serum-free medium, and then counted and adjusted to 10⁶cells/ml. 500 μl of the cell suspension was placed in the Transwellmembranes and allowed to migrate to the underside for 6 hours orovernight at 37° C. in the presence of 50 nM BSA, HIMF, or HIMF plus 25μM of the BTK inhibitor, LFM-A13. The cells were fixed in pre-cooledmethanol and stained with Coomassie Blue solution for ten minutes. Thecells on the top chamber were removed with a cotton swab, and the cellsmigrating to the underside of the filter were visualized andphotographed using a Nikon Eclipse microscope.

Immunofluorescence microscopy. Bone marrow or COS-7 cells were culturedon coverslips in DMEM containing 10% FBS and fixed in pre-cooledmethanol for 5 minutes. The cells were then permeabilized with 0.2%Triton X-100 in PBS and blocked with 0.5% bovine serum albumin in PBSfollowed by incubation with the indicated antibodies. FITC-donkeyanti-rabbit IgG and Rhodamine-donkey anti-mouse IgG were used as secondantibodies. For transfection experiments, cells were cultured overnightand transfected with indicated constructs in serum-free medium for fourhours and changed into DMEM containing 10% FBS overnight. Cells werefixed and stained as above. A 510 confocal microscope was used for theimaging.

EXAMPLE 2

BTK was pulled down by GST-HIMF. To search for HIMF binding partners, wefirst prepared bacterial lysate for GST and GST-HIMF proteins and thenconducted bone marrow cell culture for protein lysates. Glutathionesepharose-bonded GST-HIMF and GST proteins were then used to pulldownthe candidate protein from bone marrow cell lysate. As shown in FIG.1A-1B, GST-HIMF pulled down a protein of approximately 70 kd. Thecandidate band was cut from the gel and sent for mass spectrometry,where a protein corresponding to BTK, known to be involved in B cellmaturation, was identified.

To confirm our finding, we conducted two other binding experiments.First, bone marrow lysate and bacterial lysates of GST and GST-HIMF wereused in pull-down assays. BTK antibody was used for detection after thepull-down samples were run on SDS-PAGE and transferred to the PCmembrane. As indicated in FIG. 2A, GST-HIMF pulled down BTK from bonemarrow cell lysate but GST did not.

To confirm HIMF interaction with BTK in vivo and to assess its role inischemia and angiogenesis, we employed the established mouse ischemichindlimb model of angiogenesis. When we used homogenate of mouse hindlimb hypoxic tissue instead of bone marrow cell lysate in GST-HIMFpull-down assay; again BTK was shown to bind to GST-HIMF but not to GST(FIG. 1A-1B). These results further indicate that BTK is a HIMF bindingpartner.

EXAMPLE 3

Co-localization between BTK and HIMF. To demonstrate that BTK acts as aHIMF binding partner in the cells and to better understand the nature ofthis interaction, we conducted experiments to see if BTK and HIMFco-localize in bone marrow cells. Bone marrow cells were cultured oncover glasses and co-transfected with EGFP-BTK and his-HIMF plasmids. Asshown in FIG. 2, BTK and HIMF co-localized in transfected bone marrowcells.

EXAMPLE 4

Translocation of BTK in bone marrow cells in response to the stimulationof HIMF. BTK family tyrosine kinases have been shown to regulate actincytoskeleton and to mediate cell mobility in response to stimulation(20, 21). The involvement of BTK in thrombin-stimulated platelets (22,23) indicated that BTK is a mediator of cytoskeleton reorganization. Theactivation of BTK family tyrosine kinases will result in theirstimulated translocation to membrane fractions (24). As a partner ofBTK, HIMF may be involved in BTK signaling pathways and play a role inregulation of BTK activity. We therefore conducted an assay to examinewhether the distribution of BTK in bone marrow cells was altered inresponse to stimulation by HIMF. Bone marrow cells were cultured oncoverslips in 12 well plates for two days and then treated with HIMF orBSA for 5 minutes at a final concentration of 50 nM. The cells werefixed in pre-cooled methanol at −20° C. for 10 minutes and used forimmunocytochemistry. FIG. 3A-3B show that HIMF rapidly inducedrecruitment of BTK to the leading edge of cells.

EXAMPLE 5

BTK stimulated the migration of bone marrow cells. To test whether HIMFstimulates the migration of bone marrow cells, bone marrow cells werecultured in transwell plates in the presence of 50 μM BSA or HIMF. Thecells were cultured overnight, fixed in methanol and stained byCoomassie Blue solution. Cells growing on the surface of the membranewere removed by cotton tipped applicators before imaging. More cellsmigrated out of the chamber after the treatment of HIMF than thetreatment of BSA (FIG. 5A-5B). Cell migration was further determined bypartial trypsin digestion culture, leaving the cells to grow in colonieson a cover glass. In the presence of HIMF, more bone marrow cells werestimulated to migrate out of the colony compared to cells treated withbovine serum albumin (BSA) (FIG. 5A-5B).

EXAMPLE 6

HIMF stimulated CD45 positive cell migration and this migration wasblocked by the BTK inhibitor FLM-A13. Since HIMF is an inflammatoryfactor (3), the upregulation of HIMF may activate an immune response inthe hypoxic and inflammatory tissues. We therefore used CD45 antibody tocheck whether the migrating cells were CD45 positive. As we expected,most of the cells that migrated out of the colony were heavily stainedwith CD45 antibody (FIG. 6 A, B, and C). To demonstrate whether the BTKsignaling pathway is involved in the cell migration induced by HIMF, weconducted an experiment to block the activity of BTK by using LFM-A13, aBTK specific inhibitor, when the cells were treated with HIMF. As shownin FIG. 6D, BTK inhibitor LFM-A13 completely blocked the cell migrationinduced by BTK.

EXAMPLE 7

HIMF promoted angiogenesis in hypoxic tissues. Hypoxia can inducepulmonary artery adventitial remodeling and neovascularization. Theprogenitor cells derived from bone marrow may contribute to postnatalneovascularization and vascular wall thickening as occurs withdevelopment of pulmonary hypertension (25). Since HIMF can activate bonemarrow cells and induce the auto-phosphorylation of BTK and stimulatethe migration of CD 45 positive cells, HIMF may have a function inrecruiting leukocytes and progenitor cells to the hypoxic tissues. Tofurther examine whether HIMF recruits EPCs to the hypoxic tissues, BSAor HIMF was mixed with 2% agarose at a final concentration of 100 nM,gelled on ice and implanted to the sites of hypoxic tissues in mousehindlimb ischemia model. Two weeks after implantation, the tissues werecollected for sectioning and immunostaining. As shown by EPC markermolecule CD34 (FIG. 7A-7B), HIMF stimulated angiogenesis in hindlimbischemia tissues. CD34 positive cells were increased in the tissuetreated with HIMF compared to the tissue treated with control BSAcontaining gel.

EXAMPLE 8

HIMF isoforms RELMα and RELMβ, are upregulated in lungs from sclerodermaand IPAH patients. Human HIMF isoforms were measured immunochemically incontrol and scleroderma lung. Results are shown in FIG. 8. A greaterthan six-fold increase was observed.

EXAMPLE 9

Genomic studies performed from peripheral blood in patients withidiopathic pulmonary hypertension demonstrate an increase in resistinexpression.

TABLE 1 Genes showing significant changes (P < 0.05 or Q < 1% inexpression in PBMCs of IPAH patients Fold Fold-increase increase in inPAH/SS IPAH patients patients Description 5.60 6.16 Vascular endothelialgrowth factor 2.84 NS Resistin 2.22 4.87 Pre-B-cell colony enhancingfactor 1 NS 2.89 Matrix metalloproteinase 9 9gelatinase B, 92 kD Type IVcollagena 1.72 1.74 Granzyme B (cytotoxic T lymphocyte- associatedserine esterase 1)

EXAMPLE 10

Treatment of hypoxic rats with simvastatin also blocks hypoxia-inducedexpression of HIMF within the lung.

Adult male Sprague-Dawley rats were exposed (14 d) to normoxia (N),normoxia plus once daily simvastatin (20 mg/kg IP) (NS), hypoxia (10%FiO2) (H) or hypoxia plus simvastatin (HS). Western blot analysisrevealed almost complete reduction of HIMF expression in the lungs ofsimvastatin treated rats exposed to hypoxia. See FIG. 9. Beta-tubulinexpression was measured as a control and did not vary under theseconditions.

The disclosure of each reference cited is expressly incorporated herein.

REFERENCES

-   1. Teng X, Li D, Champion H C, Johns R A. FIZZ1/RELMalpha, a novel    hypoxia-induced mitogenic factor in lung with vasoconstrictive and    angiogenic properties. Circ Res. 2003; 92(10):1065-7.-   2. Wagner K F, Hellberg A K, Balenger S, Depping R, Dodd-O J, Johns    R A, Li D. Hypoxia induced mitogenic factor has antiapoptotic action    and is upregulated in the developing lung: coexpression with    hypoxia-inducible factor-2alpha. Am J Respir Cell Mol Biol. 2004;    31(3):276-282.-   3. Holcomb I N, Kabakoff R C, Chan B, Baker T W, Gurney A, Henzel W,    Nelson C, Lowman H B, Wright B D, Skelton N J, Frantz G D, Tumas D    B, Peale Jr F V, Shelton D L, Hebert C C. FIZZ1, a novel    cysteine-rich secreted protein associated with pulmonary    inflammation, defines a new gene family. EMBO J.    2000;19(15):4046-4055.-   4. Nair M G, Gallagher I J, Taylor M D, Loke P, Coulson P S, Wilson    R A, Maizels R M, Allen J E. Chitinase and Fizz family members are a    generalized feature of Nematode infection with selective    upregulation of Ym1 and Fizz1 by antigen presenting cells. Infect    Immun. 2005; 73(1):385-394.-   5. Burnett M S, Lee C W, Kinnaird T D, Stabile E, Durrani S, Dullum    M K, Devaney J M, Fishman C, Stamou S, Canos D, Zbinden S, Clavijo L    C, Jang G J, Andrews J A, Zhu J, Epstein S E. The potential role of    resistin in atherogenesis. Atherosclerosis. 2005; 182(2):241-8.-   6. Wolf G. Insulin resistance and obesity: resistin, a hormone    secreted by adipose tissue. Nutr Rev. 2004; 62(10):389-94.-   7. Chumakov A. M., T. Kubota, S. Walter, H. P. Koeffler.    Identification of murine and human XCP1 genes as    C/EBP-epsilon-dependent members of FIZZ/Resistin gene family.    Oncogene. 2004; 23(19):3414-3425.-   8. Tepper O M, Capla J M, Galiano R D, Ceradini D J, Callaghan M J,    Kleinman M E, Gurtner G C. Adult vasculogenesis occurs through in    situ recruitment, proliferation, and tubulization of circulating    bone marrow-derived cells. Blood. 2005; 105(3):1068-1077.-   9. Grant M B, May W S, Caballero S, Brown G A, Guthrie S M, Mames R    N, Byrne B J, Vaught T, Spoerri P E, Peck A B, Scott E W. Adult    hematopoietic stem cells provide functional hemangioblast activity    during retinal neovascularization. Nat Med. 2002; 8: 607-612.-   10. Zhang Z G, Zhang L, Jiang Q, and Chopp M. Bone marrow-derived    endothelial progenitor cells participate in cerebral    neovascularization after focal cerebral ishcemia in the adult mouse.    Circ Res. 2002; 90:284-288.-   11. Asahara T, Masuda H, Takahashi T, Kalka C, Pastore C, Silver M,    Kearne M, Magner M, Isner J M. Bone marrow origin of endothelial    progenitor cells responsible for postnatal vasculogenesis in    physiological and pathological neovascularization. Circ Res. 1999;    85:221-228.-   12. Lin Y, Weisdorf D J, Solovey A, Hebbel H R. Origins of    circulating endothelial cells and endothelial outgrowth from blood.    J Clin Invest. 2000; 105(1):71-77.-   13. Henrich D, Hahn P, Wahl M, Wilhelm K, Dernbach E, Dimmeler S,    and Marzi I. Serum derived from multiple trauma patients promotes    the differentiation of endothelial progenitor cells in vitro:    possible role of transforming growth factor-beta1 and vascular    endothelial growth factor165. Shock. 2004; 21(1):13-16.-   14. Scapini P, Morini M, Tecchio C, Minghelli S, Di Carlo E,    Tanghetti E, Albini A, Lowell C, Berton G, Noonan D M, Cassatella    M A. CXCL1/macrophage Inflammatory protein-2-induced angiogenesis in    vivo is mediated by neutrophil-derived vascular endothelial growth    actor-A. J Immunol. 2004; 172(8):5034-5040.-   15. Khakoo A Y, and Finkel T. Endothelial progenitor cells. Annu Rev    Med. 2005; 56:79-101.-   16. Takahashi T, Kalka C, Masuda H, Chen D, Silver M, Kearney M,    Magner M, Isner J M, Asahara T. Ischemia- and cytokine-induced    mobilization of bone marrow-derived endothelial progenitor cells for    neovascularization. Nat Med. 1999; 5(4):434-438.-   17. Reyes M, Dudek A, Jahagirdar B, Koodie L, Marker P H, Verfaillie    C M. Origin of endothelial progenitors in human postnatal bone    marrow. J Clin Invest. 2002; 109(3):337-46.-   18. Vetrie D, Vorechovsky I, Sideras P, Holland J, Davies A, Flinter    F, Hammarstorm L, Kinnon C, Levinsky R, Bobrow M, Smith C I E,    Bentley D R. The gene involved in X-linked agammaglobulinaemia is a    member of the src family of protein-tyrosine kinases. Nature. 1993;    361(6409):226-233.-   19. Thomas J D, Sideras P, Smith C I, Vorechovsky I, Chapman V, Paul    W E. Colocalization of X-linked agammaglobulinemia and X-linked    immunodeficiency genes. Science. 1993; 261(5119):355-358.-   20. Mangla A, Khare A, Vineeth V, Panday N N, Mukhopadhyay A,    Ravindran B, Bal V, George A, and Rath S. Pleiotropic consequences    of Bruton tyrosine kinase deficiency in myeloid lineages lead to    poor inflammatory responses. Blood. 2004; 104(4):1191-1197.-   21. Abassi Y A, Rehn M, Ekman N, Alitalo K, Vuori K. p130Cas couples    the tyrosine kinase Bmx/Etk with regulation of the actin    cytoskeleton and cell migration. J Biol Chem. 2003;    278(37):35636-35643.-   22. Laffargue M, Ragab-Thomas J M, Ragab A, Tuech J, Missy K,    Monnereau L, Blank U, Plantavid M, Payrastre B, Raynal P, Chap H.    Phosphoinositide 3-kinase and integrin signalling are involved in    activation of Bruton tyrosine kinase in thrombin-stimulated    platelets. FEBS Lett. 1999; 443(1):66-70.-   23. Hamazaki Y, Kojima H, Mano H, Nagata Y, Todokoro K, Abe T,    Nagasawa T. Tec is involved in G protein-coupled receptor- and    integrin-mediated signalings in human blood platelets. Oncogene.    1998; 16(21):2773-2779.-   24. Varnai P, Rother K I, Balla T. Phosphatidylinositol    3-kinase-dependent membrane association of the Bruton's tyrosine    kinase pleckstrin homology domain visualized in single living cells.    J Biol Chem. 1999; 274(16):10983-10989.-   25. Davie N J, Crossno Jr J T, Frid M G, Hofmeister S E, J. Reeves    T, Hyde D M, Carpenter C T, Brunetti J A, McNiece I K, Stenmark K R.    Hypoxia-induced pulmonary artery adventitial remodeling and    neovascularization: contribution of progenitor cells. Am J Physiol    Lung Cell Mol Physiol. 2004; 286(4):L668-L678.

1-23. (canceled)
 24. A method to diagnose pulmonary hypertension in asubject, comprising: (a) determining the amount of HIMF (SEQ ID NO: 1 or2) in a serum sample of a subject using an enzyme-linked immunosorbentassay that comprises an antibody that specifically binds Resistin orRELMbeta; and (b) diagnosing pulmonary hypertension in the subject basedon elevated levels of HIMF as compared to normal control subjects who donot have pulmonary hypertension.
 25. The method of claim 1, furthercomprising the step of administering to the subject an antibody whichspecifically binds to HIMF (SEQ ID NO: 1 or 2).